A simple and efficient method for preparing high-purity
rubidium chloride includes the following steps: Adding crude
rubidium salt to glacial
acetic acid, heating and stirring to dissolve, filtering to remove insoluble impurities, yielding a crude
rubidium salt solution in glacial
acetic acid; adding a certain amount of
antimony trichloride solution to the crude rubidium
salt solution in glacial
acetic acid, stirring the reaction to obtain a small amount of pale yellow precipitate and solution until the reaction reaches equilibrium, yielding a
clear liquid and precipitate, the precipitate being used to prepare high-purity cesium salt; secondary
precipitation: adding a certain amount of
tin tetrachloride solution in glacial acetic acid to the
clear liquid, stirring the reaction to obtain a white precipitate and solution; standing, filtering, and washing: cooling and standing the solution until the reaction reaches equilibrium, filtering, washing the precipitate with glacial acetic acid, yielding a precipitate and washing liquid;
double salt decomposition: adding high-purity water to the precipitate to form a
slurry, then adding
ammonia to adjust the pH value, filtering to obtain
tin hydroxide precipitate and
rubidium chloride solution; sending the filtrate for testing: evaporating the qualified
rubidium chloride solution to
dryness, calcining to obtain
rubidium chloride; recrystallization: obtaining the high-purity rubidium
chloride product. It has the advantages of effectively removing
cesium ions from crude rubidium salt and avoiding the influence of
alkali metal ions on the purity of the final product, without loss, and with high product purity.